15 Sagittae
Keck Observatory | ||
| Observation data J2000.0
| ||
|---|---|---|
| Constellation | Sagitta | |
| Right ascension | 20h 04m 06.22091s[1] | |
| Declination | +17° 04′ 12.6774″[1] | |
| Apparent magnitude (V) | 5.80[2] | |
| Characteristics | ||
| Evolutionary stage | main sequence | |
| Spectral type | G0V + L4[3] | |
| B−V color index | 0.600±0.005[2] | |
| Absolute magnitude (MV) | 4.55[2] | |
Inclination (i) | 97.3+0.4 −0.5° | |
| Details Gyr | ||
| 15 Sge B | ||
| Mass | 68.7+2.4 −3.1 MJup | |
| Radius | 1.0±0.4 RJup | |
| Luminosity | 0.000075±0.000016 L☉ | |
| Temperature | 1,510–1,850 K | |
| Database references | ||
| SIMBAD | data | |
15 Sagittae (15 Sge) is a
The companion is a high-mass substellar brown dwarf of spectral class L4 ± 1.5, only a few Jupiter masses below the limit for stars, in a long-period orbit around the primary star. Imaged by the Keck telescope, was the first brown dwarf candidate orbiting a sun-like star detected via imaging and is currently the only known companion brown dwarf which both has a significant radial velocity trend on the primary that has also been imaged.
The brown dwarf was originally thought to have a semi-major axis of 14 AU and a circular orbit viewed from pole-on,[8] but ten more years of observations found that the brown dwarf's orbit is viewed from nearly edge-on, is significantly eccentric and appeared to be moving in a circular orbit when first discovered, but is now approaching the primary as viewed from Earth.[3]
References
- ^ .
- ^ S2CID 119257644.
- ^ S2CID 16113054. 97.
- S2CID 51814894.
- ^ "15 Sge". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-03-24.
- S2CID 12560512.
- ^ "Brown dwarf found around nearby sun-like star" (Press release). Kamuela, Hawaii: W. M. Keck Observatory. January 1, 2002. Retrieved August 13, 2019.
- S2CID 11405638.
External links
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